1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * ld script for the x86 kernel 4 * 5 * Historic 32-bit version written by Martin Mares <mj@atrey.karlin.mff.cuni.cz> 6 * 7 * Modernisation, unification and other changes and fixes: 8 * Copyright (C) 2007-2009 Sam Ravnborg <sam@ravnborg.org> 9 * 10 * 11 * Don't define absolute symbols until and unless you know that symbol 12 * value is should remain constant even if kernel image is relocated 13 * at run time. Absolute symbols are not relocated. If symbol value should 14 * change if kernel is relocated, make the symbol section relative and 15 * put it inside the section definition. 16 */ 17 18#ifdef CONFIG_X86_32 19#define LOAD_OFFSET __PAGE_OFFSET 20#else 21#define LOAD_OFFSET __START_KERNEL_map 22#endif 23 24#define RUNTIME_DISCARD_EXIT 25#define EMITS_PT_NOTE 26#define RO_EXCEPTION_TABLE_ALIGN 16 27 28#include <asm-generic/vmlinux.lds.h> 29#include <asm/asm-offsets.h> 30#include <asm/thread_info.h> 31#include <asm/page_types.h> 32#include <asm/orc_lookup.h> 33#include <asm/cache.h> 34#include <asm/boot.h> 35 36#undef i386 /* in case the preprocessor is a 32bit one */ 37 38OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT) 39 40#ifdef CONFIG_X86_32 41OUTPUT_ARCH(i386) 42ENTRY(phys_startup_32) 43#else 44OUTPUT_ARCH(i386:x86-64) 45ENTRY(phys_startup_64) 46#endif 47 48jiffies = jiffies_64; 49 50#if defined(CONFIG_X86_64) 51/* 52 * On 64-bit, align RODATA to 2MB so we retain large page mappings for 53 * boundaries spanning kernel text, rodata and data sections. 54 * 55 * However, kernel identity mappings will have different RWX permissions 56 * to the pages mapping to text and to the pages padding (which are freed) the 57 * text section. Hence kernel identity mappings will be broken to smaller 58 * pages. For 64-bit, kernel text and kernel identity mappings are different, 59 * so we can enable protection checks as well as retain 2MB large page 60 * mappings for kernel text. 61 */ 62#define X86_ALIGN_RODATA_BEGIN . = ALIGN(HPAGE_SIZE); 63 64#define X86_ALIGN_RODATA_END \ 65 . = ALIGN(HPAGE_SIZE); \ 66 __end_rodata_hpage_align = .; \ 67 __end_rodata_aligned = .; 68 69#define ALIGN_ENTRY_TEXT_BEGIN . = ALIGN(PMD_SIZE); 70#define ALIGN_ENTRY_TEXT_END . = ALIGN(PMD_SIZE); 71 72/* 73 * This section contains data which will be mapped as decrypted. Memory 74 * encryption operates on a page basis. Make this section PMD-aligned 75 * to avoid splitting the pages while mapping the section early. 76 * 77 * Note: We use a separate section so that only this section gets 78 * decrypted to avoid exposing more than we wish. 79 */ 80#define BSS_DECRYPTED \ 81 . = ALIGN(PMD_SIZE); \ 82 __start_bss_decrypted = .; \ 83 *(.bss..decrypted); \ 84 . = ALIGN(PAGE_SIZE); \ 85 __start_bss_decrypted_unused = .; \ 86 . = ALIGN(PMD_SIZE); \ 87 __end_bss_decrypted = .; \ 88 89#else 90 91#define X86_ALIGN_RODATA_BEGIN 92#define X86_ALIGN_RODATA_END \ 93 . = ALIGN(PAGE_SIZE); \ 94 __end_rodata_aligned = .; 95 96#define ALIGN_ENTRY_TEXT_BEGIN 97#define ALIGN_ENTRY_TEXT_END 98#define BSS_DECRYPTED 99 100#endif 101 102PHDRS { 103 text PT_LOAD FLAGS(5); /* R_E */ 104 data PT_LOAD FLAGS(6); /* RW_ */ 105#ifdef CONFIG_X86_64 106#ifdef CONFIG_SMP 107 percpu PT_LOAD FLAGS(6); /* RW_ */ 108#endif 109 init PT_LOAD FLAGS(7); /* RWE */ 110#endif 111 note PT_NOTE FLAGS(0); /* ___ */ 112} 113 114SECTIONS 115{ 116#ifdef CONFIG_X86_32 117 . = LOAD_OFFSET + LOAD_PHYSICAL_ADDR; 118 phys_startup_32 = ABSOLUTE(startup_32 - LOAD_OFFSET); 119#else 120 . = __START_KERNEL; 121 phys_startup_64 = ABSOLUTE(startup_64 - LOAD_OFFSET); 122#endif 123 124 /* Text and read-only data */ 125 .text : AT(ADDR(.text) - LOAD_OFFSET) { 126 _text = .; 127 _stext = .; 128 /* bootstrapping code */ 129 HEAD_TEXT 130 TEXT_TEXT 131 SCHED_TEXT 132 CPUIDLE_TEXT 133 LOCK_TEXT 134 KPROBES_TEXT 135 ALIGN_ENTRY_TEXT_BEGIN 136 ENTRY_TEXT 137 ALIGN_ENTRY_TEXT_END 138 SOFTIRQENTRY_TEXT 139 STATIC_CALL_TEXT 140 *(.fixup) 141 *(.gnu.warning) 142 143#ifdef CONFIG_RETPOLINE 144 __indirect_thunk_start = .; 145 *(.text.__x86.indirect_thunk) 146 __indirect_thunk_end = .; 147#endif 148 } :text =0xcccc 149 150 /* End of text section, which should occupy whole number of pages */ 151 _etext = .; 152 . = ALIGN(PAGE_SIZE); 153 154 X86_ALIGN_RODATA_BEGIN 155 RO_DATA(PAGE_SIZE) 156 X86_ALIGN_RODATA_END 157 158 /* Data */ 159 .data : AT(ADDR(.data) - LOAD_OFFSET) { 160 /* Start of data section */ 161 _sdata = .; 162 163 /* init_task */ 164 INIT_TASK_DATA(THREAD_SIZE) 165 166#ifdef CONFIG_X86_32 167 /* 32 bit has nosave before _edata */ 168 NOSAVE_DATA 169#endif 170 171 PAGE_ALIGNED_DATA(PAGE_SIZE) 172 173 CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES) 174 175 DATA_DATA 176 CONSTRUCTORS 177 178 /* rarely changed data like cpu maps */ 179 READ_MOSTLY_DATA(INTERNODE_CACHE_BYTES) 180 181 /* End of data section */ 182 _edata = .; 183 } :data 184 185 BUG_TABLE 186 187 ORC_UNWIND_TABLE 188 189 . = ALIGN(PAGE_SIZE); 190 __vvar_page = .; 191 192 .vvar : AT(ADDR(.vvar) - LOAD_OFFSET) { 193 /* work around gold bug 13023 */ 194 __vvar_beginning_hack = .; 195 196 /* Place all vvars at the offsets in asm/vvar.h. */ 197#define EMIT_VVAR(name, offset) \ 198 . = __vvar_beginning_hack + offset; \ 199 *(.vvar_ ## name) 200#include <asm/vvar.h> 201#undef EMIT_VVAR 202 203 /* 204 * Pad the rest of the page with zeros. Otherwise the loader 205 * can leave garbage here. 206 */ 207 . = __vvar_beginning_hack + PAGE_SIZE; 208 } :data 209 210 . = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE); 211 212 /* Init code and data - will be freed after init */ 213 . = ALIGN(PAGE_SIZE); 214 .init.begin : AT(ADDR(.init.begin) - LOAD_OFFSET) { 215 __init_begin = .; /* paired with __init_end */ 216 } 217 218#if defined(CONFIG_X86_64) && defined(CONFIG_SMP) 219 /* 220 * percpu offsets are zero-based on SMP. PERCPU_VADDR() changes the 221 * output PHDR, so the next output section - .init.text - should 222 * start another segment - init. 223 */ 224 PERCPU_VADDR(INTERNODE_CACHE_BYTES, 0, :percpu) 225 ASSERT(SIZEOF(.data..percpu) < CONFIG_PHYSICAL_START, 226 "per-CPU data too large - increase CONFIG_PHYSICAL_START") 227#endif 228 229 INIT_TEXT_SECTION(PAGE_SIZE) 230#ifdef CONFIG_X86_64 231 :init 232#endif 233 234 /* 235 * Section for code used exclusively before alternatives are run. All 236 * references to such code must be patched out by alternatives, normally 237 * by using X86_FEATURE_ALWAYS CPU feature bit. 238 * 239 * See static_cpu_has() for an example. 240 */ 241 .altinstr_aux : AT(ADDR(.altinstr_aux) - LOAD_OFFSET) { 242 *(.altinstr_aux) 243 } 244 245 INIT_DATA_SECTION(16) 246 247 .x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) { 248 __x86_cpu_dev_start = .; 249 *(.x86_cpu_dev.init) 250 __x86_cpu_dev_end = .; 251 } 252 253#ifdef CONFIG_X86_INTEL_MID 254 .x86_intel_mid_dev.init : AT(ADDR(.x86_intel_mid_dev.init) - \ 255 LOAD_OFFSET) { 256 __x86_intel_mid_dev_start = .; 257 *(.x86_intel_mid_dev.init) 258 __x86_intel_mid_dev_end = .; 259 } 260#endif 261 262 /* 263 * start address and size of operations which during runtime 264 * can be patched with virtualization friendly instructions or 265 * baremetal native ones. Think page table operations. 266 * Details in paravirt_types.h 267 */ 268 . = ALIGN(8); 269 .parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) { 270 __parainstructions = .; 271 *(.parainstructions) 272 __parainstructions_end = .; 273 } 274 275 /* 276 * struct alt_inst entries. From the header (alternative.h): 277 * "Alternative instructions for different CPU types or capabilities" 278 * Think locking instructions on spinlocks. 279 */ 280 . = ALIGN(8); 281 .altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) { 282 __alt_instructions = .; 283 *(.altinstructions) 284 __alt_instructions_end = .; 285 } 286 287 /* 288 * And here are the replacement instructions. The linker sticks 289 * them as binary blobs. The .altinstructions has enough data to 290 * get the address and the length of them to patch the kernel safely. 291 */ 292 .altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) { 293 *(.altinstr_replacement) 294 } 295 296 /* 297 * struct iommu_table_entry entries are injected in this section. 298 * It is an array of IOMMUs which during run time gets sorted depending 299 * on its dependency order. After rootfs_initcall is complete 300 * this section can be safely removed. 301 */ 302 .iommu_table : AT(ADDR(.iommu_table) - LOAD_OFFSET) { 303 __iommu_table = .; 304 *(.iommu_table) 305 __iommu_table_end = .; 306 } 307 308 . = ALIGN(8); 309 .apicdrivers : AT(ADDR(.apicdrivers) - LOAD_OFFSET) { 310 __apicdrivers = .; 311 *(.apicdrivers); 312 __apicdrivers_end = .; 313 } 314 315 . = ALIGN(8); 316 /* 317 * .exit.text is discarded at runtime, not link time, to deal with 318 * references from .altinstructions 319 */ 320 .exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) { 321 EXIT_TEXT 322 } 323 324 .exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) { 325 EXIT_DATA 326 } 327 328#if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP) 329 PERCPU_SECTION(INTERNODE_CACHE_BYTES) 330#endif 331 332 . = ALIGN(PAGE_SIZE); 333 334 /* freed after init ends here */ 335 .init.end : AT(ADDR(.init.end) - LOAD_OFFSET) { 336 __init_end = .; 337 } 338 339 /* 340 * smp_locks might be freed after init 341 * start/end must be page aligned 342 */ 343 . = ALIGN(PAGE_SIZE); 344 .smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) { 345 __smp_locks = .; 346 *(.smp_locks) 347 . = ALIGN(PAGE_SIZE); 348 __smp_locks_end = .; 349 } 350 351#ifdef CONFIG_X86_64 352 .data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) { 353 NOSAVE_DATA 354 } 355#endif 356 357 /* BSS */ 358 . = ALIGN(PAGE_SIZE); 359 .bss : AT(ADDR(.bss) - LOAD_OFFSET) { 360 __bss_start = .; 361 *(.bss..page_aligned) 362 . = ALIGN(PAGE_SIZE); 363 *(BSS_MAIN) 364 BSS_DECRYPTED 365 . = ALIGN(PAGE_SIZE); 366 __bss_stop = .; 367 } 368 369 /* 370 * The memory occupied from _text to here, __end_of_kernel_reserve, is 371 * automatically reserved in setup_arch(). Anything after here must be 372 * explicitly reserved using memblock_reserve() or it will be discarded 373 * and treated as available memory. 374 */ 375 __end_of_kernel_reserve = .; 376 377 . = ALIGN(PAGE_SIZE); 378 .brk : AT(ADDR(.brk) - LOAD_OFFSET) { 379 __brk_base = .; 380 . += 64 * 1024; /* 64k alignment slop space */ 381 *(.brk_reservation) /* areas brk users have reserved */ 382 __brk_limit = .; 383 } 384 385 . = ALIGN(PAGE_SIZE); /* keep VO_INIT_SIZE page aligned */ 386 _end = .; 387 388#ifdef CONFIG_AMD_MEM_ENCRYPT 389 /* 390 * Early scratch/workarea section: Lives outside of the kernel proper 391 * (_text - _end). 392 * 393 * Resides after _end because even though the .brk section is after 394 * __end_of_kernel_reserve, the .brk section is later reserved as a 395 * part of the kernel. Since it is located after __end_of_kernel_reserve 396 * it will be discarded and become part of the available memory. As 397 * such, it can only be used by very early boot code and must not be 398 * needed afterwards. 399 * 400 * Currently used by SME for performing in-place encryption of the 401 * kernel during boot. Resides on a 2MB boundary to simplify the 402 * pagetable setup used for SME in-place encryption. 403 */ 404 . = ALIGN(HPAGE_SIZE); 405 .init.scratch : AT(ADDR(.init.scratch) - LOAD_OFFSET) { 406 __init_scratch_begin = .; 407 *(.init.scratch) 408 . = ALIGN(HPAGE_SIZE); 409 __init_scratch_end = .; 410 } 411#endif 412 413 STABS_DEBUG 414 DWARF_DEBUG 415 ELF_DETAILS 416 417 DISCARDS 418 419 /* 420 * Make sure that the .got.plt is either completely empty or it 421 * contains only the lazy dispatch entries. 422 */ 423 .got.plt (INFO) : { *(.got.plt) } 424 ASSERT(SIZEOF(.got.plt) == 0 || 425#ifdef CONFIG_X86_64 426 SIZEOF(.got.plt) == 0x18, 427#else 428 SIZEOF(.got.plt) == 0xc, 429#endif 430 "Unexpected GOT/PLT entries detected!") 431 432 /* 433 * Sections that should stay zero sized, which is safer to 434 * explicitly check instead of blindly discarding. 435 */ 436 .got : { 437 *(.got) *(.igot.*) 438 } 439 ASSERT(SIZEOF(.got) == 0, "Unexpected GOT entries detected!") 440 441 .plt : { 442 *(.plt) *(.plt.*) *(.iplt) 443 } 444 ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!") 445 446 .rel.dyn : { 447 *(.rel.*) *(.rel_*) 448 } 449 ASSERT(SIZEOF(.rel.dyn) == 0, "Unexpected run-time relocations (.rel) detected!") 450 451 .rela.dyn : { 452 *(.rela.*) *(.rela_*) 453 } 454 ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!") 455} 456 457/* 458 * The ASSERT() sink to . is intentional, for binutils 2.14 compatibility: 459 */ 460. = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE), 461 "kernel image bigger than KERNEL_IMAGE_SIZE"); 462 463#ifdef CONFIG_X86_64 464/* 465 * Per-cpu symbols which need to be offset from __per_cpu_load 466 * for the boot processor. 467 */ 468#define INIT_PER_CPU(x) init_per_cpu__##x = ABSOLUTE(x) + __per_cpu_load 469INIT_PER_CPU(gdt_page); 470INIT_PER_CPU(fixed_percpu_data); 471INIT_PER_CPU(irq_stack_backing_store); 472 473#ifdef CONFIG_SMP 474. = ASSERT((fixed_percpu_data == 0), 475 "fixed_percpu_data is not at start of per-cpu area"); 476#endif 477 478#endif /* CONFIG_X86_64 */ 479 480#ifdef CONFIG_KEXEC_CORE 481#include <asm/kexec.h> 482 483. = ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE, 484 "kexec control code size is too big"); 485#endif 486 487